The surface of a common optical recording medium (e.g., CD) or rewritable optical recording medium (e.g., CD-RW) may be scratched in use due to rubbing with other rough surfaces. Once these optical recording media have defects on the surfaces thereof for some reasons, such as scratching, optical media recording devices have to recognize in advance or during recording process at which address or in which sector the optical recording media have surface defects. Although data will still be recorded at addresses having these surface defects, these data will also be duplicated into another spare data area for the safety concern.
In order to know relative information of the width and address of surface defects, optical medium recording devices usually require incorporating with some other hardware. The same results can be acquired with a preset file system of the operating system. Compared with the former, the latter appears to be very complicated. On the other hand, compared with optical medium recording devices, common optical medium reading devices (e.g., CD-ROM) cannot solve the problem of surface defects of disk. Some well-known large companies like Compaq, Sony, Philips, and Microsoft constituted a Mt. Rainier group to advocate a standard of defect management into optical disc devices and operating systems so as to enhance their compatibility and surface defects managing function, thereby solving some unpredictable troubles possibly encountered when optical recording media have surface defects.